Visitors From Null Space
by AuthorOfTheUniverse2401
Summary: It has only been a week since the Eggman Empire was toppled by the Resistance, and the world is still recovering. But now Null Space portals are beginning to open up everywhere, from which strange creatures are beginning to emerge. Now, an angry warlord is attempting to pick up where Eggman left off. Thankfully, Null Space can also provide some help to deal with the problem.


**A/N:** **This story takes place in the Ben 10 Original Continuity and uses the portrayal of eleven year old Ben as seen in Omniverse. As stated in the synopsis, this takes place one week after the events of Forces.**

* * *

Green Hill Zone: a place that many creatures call home. As the name would imply, it is filled with grassy plains as far as the eye can see. In the distance, rocky cliffs can be seen spewing out breathtaking waterfalls into a large lake. Today it was quite peaceful, and why wouldn't it be? The Eggman Empire had been driven off from the place by the Resistance.

Closer to the Metropolis, things weren't quite so good.

At some point, the grassy plains were abruptly cut off and replaced with sandy deserts, as if someone had tried to force mismatching puzzle pieces together. The cliffs were spouting sand streams rather than water, and the only life here was a group of huge worm-like creatures that attacked everything in sight. The other lake that was originally here was replaced by miles of sand dunes, and the sun beat down constantly with hardly any cloud cover to offer respite from the scorching light. It was an endless sea of various shades of brown, a far cry from the colorful landscape it was before.

What caused all this? A tiring war with the nefarious Dr. Ivo Robotnik a.k.a. the Eggman. An evil man of unparalleled genius, he had nearly succeeded in conquering the entire world and building his Empire on top of it. Whatever wildlife was left after his initial attack on Green Hill Zone was captured and made to power his machines. Green Hill turned out to be the testing grounds for the gems he had discovered: the Phantom Rubies. With the sinister gems, he could warp reality itself. Because of his initial experiments in controlling the Phantom Rubies' power, he had decimated the ecosystem of Green Hill, turning the luscious grasslands into desolate deserts and leaving only one large oasis in the middle of it all.

So of course, hardly anyone took notice of the large portal that had opened in the middle of the endless sands. That is, until one lad.

* * *

Rookie (He did technically have a name, but the nickname he was given had grown on him) was having a bad day. And who wouldn't be having a bad day when he had to trek through miles of desert just to get to the last vestige of green left in the so-called "Green Hill Zone." The sun was still beating down on him, constant and unrelenting heat coursing through his body. It was most annoying.

He sighed. When he had decided to see what he could do about the fractured ecosystem in Green Hill, he hadn't expected it to be _this_ bad. Certainly, he had heard Sonic, his idol turned best friend, tell of the strange sights he had seen: gigantic and ravenous worms jumping in and out of the sand like dolphins through water, a general lack of wildlife anywhere. What Sonic had neglected to mention was how _huge_ the desert portions of Green Hill were in comparison to the oasis in the south.

The Rookie smiled to himself. Then again, it would be kind of hard to gauge the size of an area if you blazed through it in less than a minute. So far, he had been trekking for almost an hour and he was only just managing to see the oasis on the horizon.

His thoughts were interrupted by an unmistakable noise, one he thought he would never hear again. The unnatural droning of the Phantom Ruby activating.

The Rookie looked to his left, seeing the unmistakable signs of the Phantom Ruby's power: the air distorting and turning red, dark floating cubes. Then in a flash of red light, a portal opened.

The Rookie recognized it, though he had only seen it for a brief moment. It was a portal to Null Space, the endless and empty dimension discovered by Dr. Eggman through the Phantom Ruby's power. The dark hole through which nothing could be seen was simply…sitting there. It wasn't even drawing anything towards it like the one he and Sonic had been pulled through.

Then, after only being present for a few seconds, it vanished. The Rookie stepped out from behind the rock, confused at what he had seen. He looked around, trying to find that unmistakable dark pink glow that signaled the gemstone's presence. He scoured every rock, looked behind every dried-up palm tree, even dug through the sand a little.

Yet there was nothing. Rookie stood from the small hole he had dug and scratched his head in confusion. He immediately regretted it as sand showered into his bright red fur. He growled and shook himself off. He reached into his pack and pulled out his water bottle, taking a long drink.

Perhaps the desert heat was finally getting to him. It could have been a mirage he had seen just then. But he had never heard of mirages making noise before. He shrugged as he put his bottle back in his pack. Even if it wasn't a mirage, it was gone now and that was all that mattered. He sighed and looked south again. The oasis was just on the horizon. Just a little longer and he'd finally be free from this desert heat. He began walking again. He was in no rush. Besides, it wouldn't do to expend his energy in the desert like this.

* * *

Miles "Tails" Prower continued typing at the hideout's computer. Messages from all over the world were displayed on the gigantic screen that covered one wall. From here, he filtered through the messages by hand to see which ones could be regarded as high priority. Then he sent out the task forces to address the concerns of the public. It was the next step for the Resistance: first they saved the world, then they helped rebuild it. Not as simple as it sounded.

Tails sighed. Sonic was currently running through Metropolis, cleaning up the last remaining Badniks Eggman had left behind when he had retreated. Even after Tails had thought he had seen the Blue Blur die right in front of him, even after he had been rescued and brought back to Mobius after all this time, Sonic _still_ wasn't spending time with him. Certainly, his brainy side told him that the world needed Sonic now more than he needed Sonic, but his childish side was missing his best friend and hurt that he wouldn't want to spend time with him.

Tails shook his head. Focus. These messages aren't going to sort themselves. Well, they probably would if Tails had decided to install that auto-reply program into the computer's mailbox. When Knuckles had asked Tails why he hadn't done so, Tails just shrugged and said:

"A program can't tell that a person needs more help when they're injured than when their pet is stuck up a tree." Sure, doing this by hand was slower, but it allowed them to get help to the people who needed it most.

"Don't you ever get bored sifting through all those?" Tails turned around and smiled. Speak of the devil, there was the Knucklehead himself.

"My entertainment is irrelevant compared to the needs of the people," Tails replied. "Don't you have an Emerald you should be guarding?"

"Don't remind me," Knuckles said, scowling. "Putting the world back together is more important right now than looking after the Master Emerald. Trust me, as soon as we're done here, it's back to Angel Island for me."

"Is that so?" asked Tails, a mischievous grin slowly forming on his face. "So, where were you when Sonic and I were _literally_ putting the world back together after Eggman _literally_ split it apart?"

Knuckles had the grace to look guilty. "I…may have broke the Master Emerald."

Tails stood there for a moment. Then he just started laughing. "Seriously? You've got to be kidding me!"

"It's the truth!" Knuckles proclaimed angrily. "I was sitting there, minding my own business when Rouge suddenly bursts out of the ground and starts fighting me! Now, I'm kind of reluctant to fight her back –"

"I wonder why…" Tails said slyly.

"Because I have a sense of honor!" Knuckles said, pretending not to notice the heat rising to his face. "So I decide to just turn around and break the thing into little pieces!" Knuckles puffed his chest out, seeming to be proud of his quick thinking.

Tails thought for a moment, then gave his own idea. "But wouldn't that make it have been easier for her to carry the Master Emerald pieces than the whole thing?"

Knuckles stood there, seemingly frozen for a moment. Then he hung his head low in shame. "I thought it was a good idea…"

Tails laughed good-naturedly and pat his friend on the back. "Hey, you may not be the best of thinkers, but you certainly do have heart. Who was it that decided to take up the role of leader of the Resistance when I went AWOL? Who was it that went out of his way to help Sonic and I stop Metal Sonic from destroying the world? Who was it that helped us get through Sky Sanctuary to chase Dr. Eggman even after we had beat you up?"

Knuckles seemed to cheer up at that. "Thanks, Tails." Then he chuckled a bit. "You know, I'm a bit jealous of you sometimes."

Tails was taken aback. "What? Why would you be jealous of me? You're the one who's strong enough to punch through stone. You're the one with better treasure-hunting instincts than anyone I know. Well, except maybe Rouge, but that's beside the point."

"Well, you're the one who can fly, build a TV out of scrap metal, and ended up best friends with Sonic the Hedgehog. What's the ability to glide and climb walls next to someone who can fly?"

Tails considered this for a moment. "How about we both agree that everyone has their own virtues and be done with this conversation."

"Sure."

It was a good thing they had finished their conversation just then, because the computer began beeping several times. Tails hurried over and checked on it. "It's a call from Sonic!" he shouted excitedly, accepting the call. "This is Tails, coming in from headquarters. Do you read me, Sonic?"

"Loud and clear, buddy," Sonic replied. "Listen, any chance you and Knuckles could show up? We've got…problems in Metropolis."

"More robots than you expected?" Knuckles asked.

"That you, Knucklehead? No, I cleared out all the straggler robots a long time ago. It's just that there's this gigantic Null Space portal that opened up above the plaza that's kind of just…hanging there."

"Oh. That's all?" Tails asked sarcastically.

"Seriously, Tails, I could use your expertise here."

"We're on our way Sonic." Tails ended the call and turned to Knuckles. The two exchanged a confident nod, then ran out the door. Their friend needed them.

* * *

Sonic stared up at the one thing he wished he would never see again: a Null Space portal. In the brief time he had spent there with the Rookie, he had been _seriously_ creeped out by the place. A gigantic dimension filled with nothing but empty space that went on forever? He'd pass on that.

Sonic frowned at that last thought. Eggman had claimed that the dimension was empty. Yet he clearly remembered seeing vague shapes moving in the distance. At the time he had dismissed them as nothing more than illusions conjured by the Phantom Ruby to freak him out, but now he wasn't so sure. He could have sworn one of the shapes had just stopped to stare at him as he left Null Space. He felt a chill run down his spine.

"Sonic!" Sonic perked up immediately at the sound of his best friend's voice. He turned around and waved, giving his signature half-smile at both Tails and Knuckles as they arrived from the air.

"Hey guys, thanks for coming out here," he said. "Robots are easy enough to deal with, but this? This isn't something I can homing attack out of existence."

Tails landed and walked up to the portal, with Knuckles sliding across the ground to finish his glide. Tails pulled his Miles Electric transceiver out of his bag and scanned the portal.

"What I find most interesting about this is the fact that it isn't sucking everything in like the ones Infinite and Eggman created. It's just…sitting there."

"That's what I thought too," said Sonic. "Any ideas?"

Tails was typing away at his transceiver. "I'm not sure. You said that when Infinite faded away, he took his Phantom Ruby with him, right?"

"Yeah," said Sonic. "And with his special Death Egg Robot destroyed, Eggman's also disappeared. Same thing happened with the Rookie's prototype."

Tails nodded thoughtfully. He put his transceiver on the ground and picked up a small rock. He threw it into the portal. After five seconds, nothing happened. "I can't be sure until I run some tests. We'll have to go back to base and get some equipment."

"What are you going to do?" Knuckles asked.

Tails turned around. "Basic stuff, I'll send in a camera to see what's inside, use a roll of –"

Tails was cut off when he was hit on the head by a rock.

Everyone stared at the rock confusedly. Tails picked up the rock, turning it over and inspecting it. He looked back at the portal confusedly. He tossed the rock in.

"You don't think…" Sonic said, stepping forward cautiously.

"That can't be…" Tails said.

The rock flew back out of the portal, but this time Tails was able to sidestep it so that it only hit Knuckles in the face.

"Ow!" he shook his head and glared at the portal.

Sonic and Tails looked at each other. "What do you think this means?" Sonic asked.

Tails was about to respond when hell broke loose.

A gigantic red shape was thrown out of the portal to crash into a building just to their left. Everyone jumped, looking at the dust cloud the shape had thrown up. Sonic tapped his friends on the shoulder, pointing at a pile of rubble behind them. Tails and Knuckles each nodded, then ran behind the rubble. They each peeked above the rubble to look at the thing that had just flown out of Null Space.

They each stared at the unknown creature with utter dumbfounded expressions.

This creature could only be described as alien. It had bright red skin with black markings all over its body. It was wearing a white shirt with a single black stripe down the middle along with long black pants. Most shocking of all was the creature's arms. All _four_ of them. Long and muscular, they seemed to hold immense power. Each arm was longer than any of the Sonic Heroes were tall.

The creature blinked and shook its head. It looked around, looking just as confused as Team Sonic felt. Then it glared at the portal.

"Nice try, Squid-Head!" the creature shouted. "You can't get out that easy!"

The creature ran towards the portal again and jumped right back in. Team Sonic didn't even have time to exchange a confused glance before it flew back out again, sliding on its back across the ground.

Following it was one of the most terrifying creatures any of them had ever seen.

It could only be described as a monstrosity. It was even taller than the red one, having to be at least 10 feet tall. Its skin was a sickly and pale shade of green that just looked…unnatural. Its arms were even bigger than the four-armed creature's, its muscles bulging, though it only had two of them. It was wearing black armor all over its body, covering what appeared to be clusters of veins. Its face was most disturbing of all. Tentacles drooping down, a gas mask of some sort, and bright red eyes filled with the most intense loathing they had ever seen.

It marched forward, planting its clawed foot against the red one's chest. "As always, you are a fool, Tennyson," it said with a raspy voice. "The Null Void hasn't contained me before. Why would you try to contain me again?"

The red one, who was apparently named Tennyson, groaned and lifted his head. "It was better than letting you stomp around my hometown like you owned the place."

"Silence," the green one said, pressing its foot down harder, eliciting a grunt of pain from the red one. "You think that I would let you imprison me again? I have destroyed countless foes of greater strength than you before."

The red one grinned. "You say that, but you still haven't taken me down even after all this time!"

The monster's eyes were filled with even more loathing. "I look forward to prying the Omnitrix from your cold, dead body."

The monster's head was thrown forward by the impact of a blue blur.

"Who dares?" the monster demanded. Distracted by looking for the interloper, the monster failed to notice Ben Tennyson grabbing its leg and throwing him backward. Even from such an awkward angle, his incredible strength was enough to throw off his enemy. The monster snarled as it crashed to the ground and Ben got up.

"That's why you don't mess with Ben 10!" the red man said. "I don't know how many times I have to drill that into your skull before you realize that, but I'll say it until you get it!"

The monster threw himself back up. "This was not due to your own power, Tennyson!"

"He's right!" called Sonic, running up between the two with his signature grin. "That would be my power!"

Tails and Knuckles looked between them, not even acting surprised that the hedgehog that was there seconds before had suddenly disappeared.

"So, what kind of alien are you, spiny?" asked the red creature.

Sonic looked at him, eyeing his four gigantic arms. "I was about to ask you the same thing, Musclehead."

Vilgax grabbed the hedgehog, glaring at him as he struggled. "You insolent fool! You will forever regret this day, the day you opposed the great Vilgax!"

Sonic glared back at the monster. "If you're so great, how come I've never heard of you?"

"You are a moron of the highest order," said Vilgax. Then his face was replaced with a giant red fist.

"Don't ignore me!" shouted Tennyson, grabbing Sonic with his lower arms as Vilgax slid backward from the force of the punch.

"Thanks, bud!" said Sonic, standing on the ground now. "Now, time to take out the trash!" He curled into a ball, using his signature Spin Dash and rocketing forward.

Vilgax took his hands away from his face in time to see the blue blur crash into his chest, knocking him backward into a wall. He grabbed Sonic and threw him headfirst at Tennyson. He jumped over Sonic as the latter slammed into the building behind the former. When he landed, the four-armed creature clapped his hands, creating a sonic boom that pushed Vilgax back with its force.

The monster stepped forward, only for Sonic to appear in front of him from a blue streak.

"Would you quit breaking everything in sight? We only just started rebuilding this city!" Vilgax took a swipe at Sonic, only to be met with empty air. A blue streak slammed into Vilgax's face, then bounced off his back, then began running around Vilgax, creating a wall of blue light. Vilgax looked around, bemused at this turn of events. He then swiped at Sonic, slamming him against the building next to them. Sonic groaned, sliding down the wall and falling to the ground.

"Sonic!" cried Tails, taking to the air again. Vilgax snapped his head around, glaring at the little fox. He jumped at him, claws outstretched. Then Knuckles jumped at him from the top of a building and tackled him to the ground. Vilgax stood up, shaking his head and throwing the Echidna off him. Tails hurried over to Knuckles to help him up. Then two gigantic red arms wrapped around Vilgax's neck and trapped him in a headlock. Two others pinned his arms to his sides

"It's over, Vilgax!" Tennyson said. "Now what say you get in the Null Void and never come back out?"

"I have a better idea," Vilgax said. "Submit to me and die a quick and painless death."

"Yeah, like that's gonna –" His words were cut off by the sound of a high pitched beeping noise. Tails and Knuckles looked and saw something they hadn't noticed before: a strange symbol on Tennyson's shoulder that was currently flashing red. Tennyson suddenly appeared worried and ran toward the Null Space portal, dragging Vilgax with him.

"Release me and die!" Vilgax cried.

"Sorry, no time for that!" said Tennyson over the beeping, throwing Vilgax into the portal.

Then the beeping turned into a low droning noise and everyone was blinded by a flash of red light.

Tails's head was drawn to the Null Space portal, where the sound of howling wind was coming from. When he was able to see again, Tails saw the Null Space portal was slowly getting smaller. Vilgax's outstretched claw briefly appeared from the portal, then disappeared along with the portal.

"I don't think he'll be coming back anytime soon," said Knuckles.

"You can say that again," said an unfamiliar voice.

Tails and Knuckles turned and stared at the source of the voice.

It was a small boy, standing right where Tennyson was. He was only a head taller than Sonic, wearing the same white shirt with a single black stripe as Tennyson. He had baggy green pants, black and white sneakers, and a black watch on his wrist with the same symbol Tennyson had on his shoulder.

"Who the heck are you?" Tails asked.

"Tennyson" gave Tails a confused look. "Are you kidding?" he asked. "I'm Ben Tennyson!"

He was met with blank looks from both Tails and Knuckles. Ben crossed his arms. "Ben 10?" No response. He sighed.

"Guess I have some explaining to do."

* * *

 **A/N:** **Right, as Ben said, time to explain some things.**

 **First, I'll be referring to the Custom Avatar/Player Character/Fursona/Whatever the heck you want to call him by the name Rookie. Yes, I realize that's a bit ridiculous, but I feel I should remind you that there's a Bee named Charmy, a rabbit named Cream and her pet Cheese, an Echidna named Knuckles, and a fox named Miles Prower in the Sonic universe. Compared to that, Rookie is an all-around normal name.**

 **Second, Rookie won't be speaking that much if at all in this series. Some might say this will make it difficult to give him character. I refer you to the Metroid series (Other M notwithstanding) and the first Jak and Daxter game for examples of silent protagonists with plenty of character.**

 **Please do tell me how I can improve my writing and what you thought of the story overall. Thank you for your time.**


End file.
